/*
 * SonarQube, open source software quality management tool.
 * Copyright (C) 2008-2014 SonarSource
 * mailto:contact AT sonarsource DOT com
 *
 * SonarQube is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * SonarQube is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.batch.components;

import org.sonar.api.BatchExtension;
import org.sonar.api.CoreProperties;
import org.sonar.api.batch.Event;
import org.sonar.api.database.DatabaseSession;
import org.sonar.api.database.model.Snapshot;

import java.util.List;

public class PastSnapshotFinderByPreviousVersion implements BatchExtension {

  private final DatabaseSession session;

  public PastSnapshotFinderByPreviousVersion(DatabaseSession session) {
    this.session = session;
  }

  PastSnapshot findByPreviousVersion(Snapshot projectSnapshot) {
    String currentVersion = projectSnapshot.getVersion();
    Integer resourceId = projectSnapshot.getResourceId();

    String hql = "from " + Event.class.getSimpleName() +
      " where name<>:version AND category='Version' AND resourceId=:resourceId ORDER BY date DESC";

    List<Event> events = session.createQuery(hql)
        .setParameter("version", currentVersion)
        .setParameter("resourceId", resourceId)
        .setMaxResults(1)
        .getResultList();

    if (events.isEmpty()) {
      return new PastSnapshot(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_VERSION);
    }

    Event previousVersionEvent = events.get(0);
    Snapshot snapshot = session.getSingleResult(Snapshot.class, "id", previousVersionEvent.getSnapshot().getId());

    return new PastSnapshot(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_VERSION, snapshot.getCreatedAt(), snapshot).setModeParameter(snapshot.getVersion());
  }

}
